1. Technical Field
The present invention relates generally to seat back adjustment mechanisms and more particularly to a seat back adjustment mechanism that enables a seat back to be locked in a forward fold-down position to remain substantially horizontal.
2. Discussion
Vehicle markets such as mini-van and sport utility are extremely competitive and a focus for improvement by automobile manufacturers. Specifically, automobile manufacturers seek to improve the overall utility and comfort of the vehicles in these markets in pursuit of attracting and keeping customers. One important feature is a flexible vehicle interior. Flexibility, in this sense, refers to the interior""s ability to provide seating that may be modified to suit a particular customer""s needs. For example, a customer might desire the removal of a rear seat to provide increased cargo space, while maintaining a middle seat or seats for additional passengers. Additionally, a passenger might desire the seat back of a front or middle seat to fold down, providing a work space while traveling. As such, a passenger could place a laptop computer on the folded down seat back or use the folded down seat back as a small desk for writing or reading.
As is known in the art, a seat back may be reclined to various recline positions providing occupant comfort. Concurrently, the seat back may be dumped to a fold forward position for providing improved access to a vehicle interior or a work space, as discussed above. Traditional seat back adjustment mechanisms retain a specific disadvantage in that the recline position of the seat back, prior to folding the seat back forward, defines the fold forward position of the seat back relative to horizontal. For example, if the seat back is in a fully reclined position prior to being folded forward, in the fold forward position the seat back will be at a substantial angle relative to horizontal. This is undesirable, particularly in the case of using the seat back as a work space.
It is therefore desirable in the industry to provide a fold-forward adjustment mechanism for use with a seat back that enables an operator to fold the seat back in a generally horizontal or fold-flat position regardless of the initial reclined position of the seat back relative to the seat.
Accordingly, the present invention provides a seat adjustment mechanism including an arm rotatably defining a first locking shoulder, a sector plate rotatably supported by the arm and defining a second locking shoulder having a lock recess, a locking member selectively engaging at least one of the first and second locking shoulders, a quadrant rotatably supported by the arm and slidably supporting the locking member for locking the quadrant in one of a first and second position relative to the arm and a cam plate rotatably supported by the quadrant for selectively engaging the locking member for locking the quadrant in one of the first and second positions. In the first position the locking member is biased against the first locking shoulder and in the second position the locking member is biased into the lock recess. A gear assembly is preferably provided and operably supported by the quadrant for actuation of the cam plate. The gear assembly preferably includes a first gear plate rotatably supported by the quadrant and a second gear plate in meshed engagement with the first gear plate and in operable communication with the cam plate for selectively imparting rotation of the cam plate.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.